Safety lock for license plates



March 21, 1950 w. T. MARTIN SAFETY LOCK FOR LICENSE PLATES Filed Jan. 17, 1947 2 Sheets-Sheet l INVENTOR. WIL iAMT. MARTIN v rron/vars.

March 21, 1950 w. 1-. MARTIN SAFETY Locx FOR LICENSE PLATES 2 Sheets-Sheet 2 Filed Jan. 17-, 1947 nvmvroza. WILLIAM T MARTIN I A TrdRNEYs Patented Mar. 21, 1950 UNITED S TAT ES PATENT *QFFICE SAFETY LGCK' FOR LICENSE PLATES Williama'l.:Martimflampa,.Fla.

Application January 17, 1947,1"SeriaYNo?722,636

it'impossible to remove theplate-without destroy- 'ing orsubstantially damaging it.

Otheradvantages of theinvention are that the protective embossment hereinafter described may be stamped out in the same operation in which-the plate itself is stamped, and thebolt and nut are ofsimple and easily manufactured "design.

Other objects Will'be in partobviousfrom the annexed drawing and in part hereinafter indicated in'connection therewith by the follow- 'ing analysis of this invention.

This invention accordingly consists in the features of construction, combination of parts, and in the unique relation of the membersand in the "relative proportioning and disposition thereof, all as more completely outlined herein.

To enable others skilled in the art fully to comprehend the underlying features'of this invention, that they may embody thesame by the modifications in structureand relation contemplated by the invention, a drawing depicting the preferred embodiment of the invention forms a :part of this :disclosure, and in such drawing like characters of reference "denote corresponding parts throughout the several views.

"In the "drawings;

*Figil is a fronttview' showingmy new. license ioridisplayiplate.

'--Fig. 22 is'a. cross-sectioni taken along the line Fig. 3 is a top view showing the plate attached to an ordinary holder.

Fig. 4 is a front view showing the plate attached to an ordinary holder.

Fig. 5 is a cross-sectional view of the assembled device, taken along the line 5-5 of Fig. 4.

Fig. 6 is a side view of the bolt used in attaching the plate to the holder.

Fig. 7 is a side view of the nut into which the bolt is screwed.

Fig.i8'is aview of the" inner face of thenut. Fig. 9'is a front view showing my device when appliedto-a: clipfor looking on a present style license plate.

Fig; 10 is across-sectionalview taken along the line ill-l0 of Fig. '9.

-Fig; 11 shows my device as appliedto an annual tab used in' thosestateswhich do-not issue complete new license tags every year.

In the constructionillustrated, a license plate I2 havingapertures l3 for fastenings' of theusual form, isprovided with raised protective embossments 1-4 surrounding the aperturesthe area contained within said embossments' being slightly greater than the area of'the respective apertures, thus forming a ledge to support thebolt headz23,--said embossments being in'turn surroundedby perforations I5. In Fig. 4 is shown a conventional license'plate holder l5 having 'slots- I! for the securing means. The license p ate i2 is so'positioned adjacent theholder I 6 that at least one of the apertures l3 in the plate l2 registers with one of the slots I! in the holder I5. Asnut' l9, has ai threaded recess 20, anda protuberance "2i the height of which fromthe surface of the nut is substantia ly the same as the thickness'of the license plate holder [6. The

widthof this-protuberance ii is slightly less than :the width of the slots l1 and its length is substantially greater than the width of said slots sothat it fits loosely therein and holds the nut against rotation in assembled position.

The protuberance 2| of the nut l 9, having been positionedwithin'the slots I Tin the holder l6,

so that the threaded recess 20 is aligned with the aperture l3 in the license plate 12, and the aper- -ture l Tin theholder16. A threaded bolti22,

having a head 23 with a screw driver slot so designed that the bolt may be turned in one'di- -rection only, is inserted in the aperture l3 of the plate I2, passed'through the slot I! in the holder ="I6-and' screwed-into the threade -recess "2U 61 'the nut l9.

' This havingbeen-donei'the bolt cannot-be unscrewed'by arotated blade, due tothe beveled construction of the slot in its head. The nut cannot be turned, due to the fact that the protuberance thereof is held by the slot in the holder, and the bolt cannot be turned by pliers or similar tools, since access to the sides of the head is prevented by the protective embossment. In order to remove the plate, substantial pressure must be applied near the weakened por-- tions I5 of the plate thus tearing the plate loose by breaking it at the weakened points. The bolt may then be removed by gripping the embossment with pliers or other grasping means so tightly that the inside thereof is pressed against the head of the bolt, and then unscrewing the bolt by turning it together with the portion of the embossed plate remaining in place. The side of the bolt-head may be roughened, as shown in Fig. 6, in order to facilitate its removal in this manner.

The same method may be used for the attachment of an annual tab 24 as shown in Fig. 11, in which 25 represents a slot in the plate 26, and 21 is a projection of the annual tab 24 fitting into the slot 25 the width of which projection 21 may be less than that of the annual tab. The tab is then fastened on in exactly the same manner as the full-size license plate hereinbefore described, by a bolt of the type shown in Fig. 6 passing through an aperture 13' in the tab and an aperture in the license plate and screwing into a nut of the type illustrated in Figs. '7 and 8. Application of pliers or similar tools to the head of the bolt is prevented by an embossment l4 surrounding the aperture 13' in the tab. Said embossment is in turn surrounded by a weakened portion 15 of the tab 24, in order that it may be removed at the end of the year, in the manner hereinbefore described in connection with the full-size plate.

A form of my invention may also be used, as shown in Figs. 9 and 10, to lock on a license plate of the present type which possesses no protective embossment for the bolt-head. This is accomplished by the use of a metal clip 28, comprising two arms 29 and 30. The arm 29 is designed to fit over the front of the plate and has an aperture 13", and surrounding protective embossment M" in turn surrounded by weakened portion 15" of the fork 29, just as hereinbefore described in connection with other forms of my invention. Said aperture 13 is so placed as to register with the usual aperture 33 in a license plate 3| when the bracket is fitted thereon. Fork 3!! possesses an aperture 32 in like position, and after the bracket has been put in place the shank of the bolt 22 is passed in turn through the aperture 13', 33 and 32, and then screwed into a nut of the type illustrated in Figs. 7 and 8, all as shown in cross section in Fig. 10. Since this nut cannot the plate.

I claim: 1. In combination, a plate adapted for attachment to a holder having a slot therein, said 'plate having an aperture therein and a raised circular protective embossment surrounding said aperture but spaced therefrom to form a small recess, a bolt having a head fitting into said recess and so designed that it may be turned in only one direction by a rotated blade, the portion of the plate surrounding the embossment being weaker than the rest of the plate so that said embossment may be crushed into frictional engagement with said bolt head thereby permitting removal of said bolt by the application of rotary force to the sides of said bolt head through said crushed embossment, and a nut having a proturberance with at least two parallel sides, said protuberance fitting into the slot in said holder with said parallel sides aligned with the sides of the slot, the length of said parallel sides of the protuberance being substantially greater than the width of the slot.

2. A combination as claimed in claim 1 in which the sides of the bolt head are roughened to facilitate engagement with said crushed embossment.

3. In combination, a plate and locking device as claimed in claim 1, said plate constituting an annual tab for an automobile license tag, and an automobile license tag having at least two slots, one of said slots being adapted to pass said bolt and the other to receive one end of said annual tab.

4. In combination, a plate and locking device as claimed in claim 1, said plate constituting an annual tab for an automobile license and .carrying a tongue protruding from one edge thereof, and a license tag having at least two slots, one of said slots being adapted to pass said bolt and the other having a length slightly greater than the width of said tongue and positioned on the license plate at a distance from the center of said first slot approximately equal to the distance from the aperture in said annual tab to the edge of said tabsupporting said tongue, and extending in a direction parallel to said edge, so as to receive said tongue when the aperture in said tab is so placed as to register against said first mentioned slot in said tag.

5. In combination a plate and locking device as claimed in claim 1, said plate constituting an annual tab for a license plate and having two parallel arms adapted to fit over one edge of said license plate, one of said arms carrying the aperture and surrounding embossment described in claim 1 and the other carrying a registering aperture.

WILLIAM T. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,429,347 Hough Sept. 19, 1922 1,809,465 Wheeler et a1. June 9, 1931 1,925,667 Kirton Sept. 5, 1933 1,929,116 Kirton Oct. 3, 1933 1,970,461 Kirton Aug. 14, 1934 2,042,267 McCulloch May 26, 1936 2,046,571 McCain July 7, 1936 2,122,557 Canter July 5, 1938 

